Finite Element Analysis of Revolute Manipulators With Link and Joint Compliance by Joint-Beam Elements

Abstract

Abstract In this paper, a composite finite element, referred to here as a joint-beam element, is presented to facilitate finite element modeling of revolute-jointed manipulators with both link and joint compliance. This element is primarily composed of two adjacent Euler beams joined by a torsional shaft in such a way that one end of the shaft can be kinematically rotated. Also accounted for in this element are the lumped mass and inertia moment representing the mass properties for the corresponding joint actuator. Through a number of cases studied using this element along with standard beam elements, the effect of joint compliance on the overall dynamic performance for a completely flexible manipulator is investigated. In particular, the joint compliance as well as link compliance are found to have significant impact on the positioning deviation of a robot, depending upon the relative amounts of joint and link flexibility. Useful information is obtained for improved design of completely flexible manipulators to reduce dynamically induced positioning errors.